In a typical phone handset of a cellular or mobile phone, a mobile identification number (MIN), i.e. the dialable phone number, and other numbers specific to the cellular phone carrier are usually programmed into the phone through a keypad interface. One of the numbers, a service programming code, is typically a five-digit or six-digit number that may be predefined or randomly assigned. The service programming code may be used to prevent a user from authorized or unauthorized changing the MIN of the cellular phone, but up to this time, the service programming code is often the same number for all cellular phones enrolled with a particular carrier. Once this number is known, the user may change the phone's MIN of a first phone carrier to another MIN from a second carrier without the approval of the first carrier. In order for the user to be locked out of reprogramming the MIN of a phone, the security programming code in each phone would have to be set to a unique number by the phone carrier and would have to be tracked in customer records.
The manual programming mechanisms for programming a cellular phone that are used today do not limit the user from switching to another MIN or another cellular service provider. It is advantageous in some instances, such as during an equipment lease agreement or with embedded phones inside telematics units, for the cellular service provider or equipment manufacturer to control the calling access for a cellular phone and to limit the ability for anyone to change the phone number of the phone.
It is desirable, therefore, to provide a system and method that overcomes the challenges and obstacles described above by controlling the calling access of a cellular phone, and more specifically, the ability for a user to change the phone number and cellular service provider that provide phone connectivity to an in-vehicle telematics unit.